The field of the invention relates to cardiac defibrillation and more particularly to portable defibrillators and patient monitoring.
Cardiac arrest can occur in humans for any of a number of reasons. Triggering events may include heart attack, accidental contact with high voltage sources or disease. While the term xe2x80x9ccardiac arrestxe2x80x9d suggests a total cessation of heart function, a more accurate characterization may be a lack of coordinated contractions among the various segments of the heart. The lack of coordinated contractions may be further characterized by the term xe2x80x9cfibrillationxe2x80x9d. Often cardiac arrest may be reversed through application of an electric shock from a defibrillator.
Defibrillators have been constructed to operate under a number of different modes. Under a first mode, a defibrillator may deliver a one-time shock (usually in the case of full cardiac arrest) under control of an operator. Under other modes, the defibrillator may receive an R-marker from a heart monitor for other therapeutic processes (e.g., demand pacing, cardioversion, etc.).
The transport of critically ill patients may require the use of a cardiac monitor to monitor the patient""s condition. In the case of the sudden onset of cardiac failure, it is often necessary to use defibrillators while transporting the patient (e.g., within a hospital, emergency vehicle, aircraft, etc.). Where used during transport, a defibrillator must rely upon battery power. However, batteries often deteriorate or become discharged during use. Because of the importance of defibrillators, a need exists for a more reliable method of supplying power to defibrillators during transport.
In addition, it is cumbersome to carry multiple instruments for cardiac monitoring and defibrillation. Further, users prefer not to carry more equipment than they need, therefore it is desirable to be able to separate defibrillator functions from monitoring functions.
A method and apparatus are provided for distributing power within a cardiac treatment and monitoring system which includes a defibrillator releasably coupled to a patient monitoring unit. The monitoring unit may be used to supply power to the defibrillator when it is operating on AC mains power, and also when operating on battery power if the monitor is equipped with an equal or greater number of user-exchangeable battery packs.